1. Technical Field
The present invention relates to a circuit device, a power receiving device, an electronic apparatus, and the like.
2. Related Art
In recent years, batteries (secondary batteries) have been widely used as a power supply for mobile apparatuses and the like. Batteries can be repeatedly used by being charged. In such a case, it is recommended that the batteries are charged using methods appropriate for the characteristics of the respective batteries.
A technology disclosed in JP-A-10-98836 is a known technology of the method used when a battery is charged. In this known technology, a charge voltage, temperature, and a terminal voltage of the battery are measured, and when the measurement values deviate from an allowable range, the application of a charge voltage is interrupted once, and when the measurement values enter the allowable range, the application of the charge voltage is restarted.
Various paths for supplying power from a battery to a power supply target can be envisioned according to the specification or the like of the power supply target. For example, in the case where an operation voltage of the power supply target is lower than the output voltage of the battery, it is conceived that the output voltage of the battery is stepped down by a charge pump circuit and the stepped down voltage is supplied to the power supply target. At this time, there are cases where some kind of voltage is applied to the output of the charge pump circuit. For example, in a hearing aid, power is supplied from a device for tuning to the hearing aid, and the voltage of the supplied power is applied to the output of the charge pump circuit. In this case, depending on a condition regarding the voltage generated by stepping down the output voltage of the battery and the voltage applied to the output of the charge pump circuit, uncontrolled charging occurs from the charge pump circuit to the battery, and an over-voltage or an over-current may possibly be applied to the battery.